This invention relates to keyboards and more particularly to a long travel, high tactile feedback keyboard and method of making same.
Many of the current keyboards used in commercial calculators today are mechanical in nature and consist of numerous metal strips and springs that provide the switch mechanism and tactile feedback. This type of mechanical configuration has some severe limitations in that it produces keyboards which have poor reliability, high cost and high labor content. Other types of keyboards, such as that disclosed in U.S. Pat. No. 4,081,898 entitled "Method of Manufacturing an Electronic Calculator Utilizing a Flexible Carrier", solves some of these problems in that this type of calculator uses a flexible substrate carrier folded back upon itself with an insulator therebetween; the flexible substrate has protuberances located thereon with a conductor strip on the underneath side such that when the protuberance is depressed, an electrical connection is made. This type of keyboard has improved the reliability and reduced the cost of keyboards to some extent but is not desirable for business-type data entry machines or calculators in which the operators that use these type machines apply the touch method and therefore need to use keyboards which have a long travel distance and high tactile feedback characteristic. In other words, the key must snap back such that the operator has assured himself that in fact an input (or electrical connection) has been made. Utilizing keyboards which have a short travel distance will not give the operator the feeling of confidence that an input or electrical connection has been made.